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Unified model of disturbances acting upon gimbal seeker in anti-tank guided missile

Nawrocki Radosław

Journal of Automation Mobile Robotics and Intelligent Systems

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2021

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Vol. 15, No. 3

54--69

EN

Optimisation of the dynamic response of gimbal seeker plays key role from the point of view of development of anti-tank guided missile’s systems. In this study the set of the most important internal disturbances were integrated in generalized model of two axis gimbal seeker implemented in MathWorks’ Simulink environment. Compared to previous works on the subject, it was enhanced by replacing simple friction model with dynamic LuGre friction. Furthermore, its Coulomb component was linked to the normal force induced by missile’s lateral acceleration. Control system of gimbal seeker proposed in paper was tuned with modelled disturbances turned off and then examined with them being turned one by one. System’s responses were assessed to be significantly deteriorated, proving need of disturbance modelling and its use in control systems’ design.

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A New Design Methodology For Enhancing The Transient Loading Of Low Drop-out Regulators (LDRs)

Abdel-Monem Ahmed, El-Mashade Mohamed B., Dabbous T. E.

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 2

319--327

EN

A new simple design methodology which makes LDR output nearly insensitive to jumps of the load current for long times is proposed. This methodology is tested for more than 10⁴ seconds. Our procedure leans on cross coupling of the time second derivative of the LDR power transistor gate and drain voltages along with their currents. This technique keeps low values of these currents in order of nano or hundreds of micro amperes for undershot or overshot cases, respectively. The introduced methodology has been applied to a standard CMOS of 0.18μm technology for NMOS transistors and validated using MATLAB R2014a.

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Breaking the Testing Pyramid with Virtual Testing and Hybrid Simulation

You Shawn, Gao Shawn, Nelson Arlin

Fatigue of Aircraft Structures

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2019

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Iss. 11

1--10

EN

Virtual testing and hybrid simulation have become an important trend in airplane design and validation. The traditional Testing Pyramid (or Building Block) approaches that emphasis on uniaxial coupon test and full structure certification test are being challenged. Researchers are trying to use advanced testing and simulation methods to replace the Testing Pyramid approach. Before physical testing, virtual testing can be conducted to simulate the physical test. Virtual model of the full testing system including controller, actuators, and fixtures can be constructed and validated. In this work, an example has been developed and validated to show the potentials of the virtual testing process. Hybrid simulation is an approach of analyzing an analysis model and physical structure integrated system under realistic loading conditions. Hybrid simulation combines the lab testing with numerical analysis to explore the benefits of both methodologies. In this study, a hybrid simulation for a simplified airplane wing was conducted to demonstrate the process. Virtual testing and hybrid simulation are alternative methods of Testing Pyramid approach. Full scale tests are still required for certification but the more that is known about the test article, the greater chances of success in the full-scale certification testing.